1～21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量的研究

本试验旨在研究饲粮不同硒添加水平对1~21日龄岭南黄羽肉仔鸡生长性能和抗氧化性能的影响,以探讨快大型岭南黄羽肉仔鸡饲养前期的饲粮硒适宜供给量。选用1日龄健康、发育良好的快大型岭南黄羽肉公雏鸡1 200只,根据体重随机分为5个组,每组6个重复,每个重复40只鸡,试验1组(对照组)饲喂基础饲粮(硒水平为0.039 mg/kg),试验2~5组饲粮在基础饲粮中分别添加0.075、0.150、0.225和0.300 mg/kg硒,试验期21 d。结果表明:本试验条件下:1)与对照组相比,饲粮添加0.300 mg/kg硒显著降低1~21日龄岭南黄羽肉仔鸡的末重(P0.05),显著提高料重比(P0.05),且0.300 mg/kg硒添加组的平均日增重显著低于其他各水平硒添加组(P0.05)。2)与对照组相比,饲粮添加0.075和0.150 mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的血浆谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),饲粮添加0.225和0.300 mg/kg硒显著降低血浆丙二醛(MDA)含量(P0.05)。各水平硒添加组的红细胞GSH-Px活性均显著高于对照组(P0.05)。3)与对照组相比,饲粮添加0.075、0.150和0.225mg/kg硒显著提高21日龄岭南黄羽肉仔鸡的肝脏GSH-Px活性(P0.05),0.075和0.150 mg/kg硒添加组的肝脏MDA含量显著低于对照组和0.300 mg/kg硒添加组(P0.05)。综合考虑,为获得较好生长性能和抗氧化性能,1~21日龄岭南黄羽肉仔鸡饲粮硒适宜添加水平为0.075 mg/kg,基础饲粮中硒水平为0.039 mg/kg,则1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.114 mg/kg;以肝脏MDA含量为依据,通过非线性回归分析估测得到1~21日龄岭南黄羽肉仔鸡饲粮硒适宜供给量为0.130 mg/kg。

Optimal Dietary Selenium Allowance for Lingnan Yellow-Feathered Broilers Aged from 1 to 21 Days

This experiment was conducted to investigate the effects of dietary different selenium levels on growth performance and antioxidant property of Lingnan yellow-feathered broilers aged from 1 to 21 days, in order to estimate the optimal dietary selenium allowance of fast-growing Lingnan yellow-feathered broilers in the early feeding period. One thousand and two hundred 1-day-old healthy, well-developmental, fast-growing Lingnan yellow-feathered male broilers were randomly assigned to five groups with six replicates per group and forty broilers per replicate according to the body weight. The broilers in experimental group 1 ( control group) were fed the basal diet ( the level of selenium was 0. 039 mg/kg) , and those in experimental groups 2 to 5 were fed the basal diet supplemented with 0.075, 0.150, 0.225 and 0.300 mg/kg selenium, respectively. The experiment lasted for 21 days. The results showed as follows: under the experiment condition, 1) compared with the control group, the diet supplemented with 0. 300 mg/kg selenium significantly decreased the final weight and increased the ratio of feed to gain of Lingnan yellow-feathered broilers aged from 1 to 21 days ( P<0.05), and the average daily gain (ADG) in 0.300 mg/kg selenium supplemental group was significantly lower than that in the other selenium supplemental groups ( P<0.05) . 2) Compared with the control group, the diet supplemented with 0.075 and 0.150 mg/kg selenium significantly increased the activity of glutathione per-oxidase ( GSH-Px) in plasma of Lingnan yellow-feathered broilers at 21 days of age ( P<0.05) , and the diet supplemented with 0. 225 and 0.300 mg/kg selenium significantly decreased the content of malondialdehyde (MDA) in plasma (P<0.05).The activity of GSH-Px in erythrocyte in all selenium supplemental groups was significantly higher than that in the control group (P<0.05). 3) Compared with the control group, the diet supplemented with 0.075, 0.150 and 0.225 mg/kg selenium significantly increased the activity of GSH-Px in liver of Lingnan yellow-feathered broilers at 21 days of age (P<0.05), and the content of MDA in liver in 0.075 and 0.150 mg/kg selenium supplemental groups was significantly lower than that in the control group and 0.300 mg/kg selenium supplemental group (P<0.05). In conclusion, based on the growth performance and antioxidant property, the optimal dietary selenium supplemental level of Lingnan yellow-feathered broilers aged from 1 to 21 days is 0.075 mg/kg, base of 0.039 mg/kg of selenium level in the basal diet, the optimal dietary selenium allowance of Lingnan yellow-feathered broilers aged from 1 to 21 days is 0.114 mg/kg. Based on the content of MDA in liver, the optimal dietary selenium allowance of Lingnan yellow-feathered broilers aged from 1 to 21 days estimated by nonlinear regression analysis is 0.130 mg/kg.